Use the same string for 2FA failures

app/controllers/user/sessions_controller.rb

@@ -22,7 +22,7 @@ class User::SessionsController < Devise::SessionsController
           continue_sign_in(resource, resource_name)
         else
           sign_out(resource)
-          flash[:error] = "Invalid code provided"
+          flash[:error] = t('views.auth.2fa.errors.invalid_code')
           redirect_to new_user_session_url
         end
       end

app/controllers/user_controller.rb

@@ -190,10 +190,10 @@ class UserController < ApplicationController
     current_user.otp_module = :enabled
 
     if current_user.authenticate_otp(req_params[:otp_validation])
-      flash[:success] = 'Two factor authentication has been enabled for your account.'
+      flash[:success] = I18n.t('views.auth.2fa.setup.success')
       current_user.save!
     else
-      flash[:error] = 'The code you entered was invalid.'
+      flash[:error] = t('views.auth.2fa.errors.invalid_code')
     end
 
     redirect_to edit_user_security_path

config/locales/en.yml

@@ -452,3 +452,7 @@ en:
       2fa:
         title: "Two-factor authentication"
         otp_field: "One-time password"
+        errors:
+          invalid_code: ""
+        setup:
+          success: "Two factor authentication has been enabled for your account."